Despite the warm weather and extra free time, the summer can be a difficult season to stay physically fit. Many people will leave their gym subscriptions behind to take a vacation, where staying in shape might fall to the bottom of priority lists.

But there are plenty of exercises that don't require gym equipment.

Here are a ten suggestions from physical trainers in the Hanover-Adams area:

1. Interval training

Sprint on a track, the beach or your backyard for 30 seconds and rest for 90 seconds. Repeat.

"This will help boost your metabolism and burn calories at a higher rate for the rest of the day," said Brett Swope, the founder and CEO of Elite Sports Performance in New Oxford.

2. Leave the car behind for a day

"Try to walk to different places instead of driving. Try to do something active on your vacation like hiking or anything active outside other than sitting down," Hanover Area YMCA Health and Wellness Director Adam Wildasin said. "If you're going to the beach, try to get in the water and swim around a little bit."

The exercise also consumes more energy than running on asphalt, burning more calories per mile, he said.

4. Body-weight squats

Gold's Gym trainer Tim Knaub suggests doing squats, which can be as simple as repeatedly sitting down on a couch or chair and standing back up.

"If you're not sure how to squat, the easiest way to do it is to sit down and stand back up because that's basically what it is," he said. "Your legs are the biggest muscles in your body. If you can build leg strength up, you can build muscle. The more muscle in your body that you have, the more calories you burn without having to exercise."

5. Put a wall to good use

Try doing wall sits to exercise your quads, hamstrings and glutes.

"Find a wall and put your back on it, then bend your knees while keeping your back flat against the wall," Wildasin said. "Hold that for 20 seconds or more, depending on your fitness level."

6. Find creative ways to use common park equipment

When you are on vacation and still want to continue with your training you will have to get creative, Swope said.

"Most places we vacation have a playground," he said. "This is a great place for pull-ups, push-ups and dips."

7. Make the most of TV-watching time

Many exercises that don't require equipment can be done while watching TV.

For example, work triceps by doing dips, the inverse of a pull-up. Start by placing your hands on a surface behind you, like a couch, and bending your elbows to achieve a 90-degree angle. Then, straighten your arms again to complete one dip.

"Those are something you can do while you're watching TV, when a commercial comes on," Wildasin said.

8. Drink a lot of water

Nutrition is an important element of physical fitness, and drinking water is healthier than other drinks and can boost metabolism.

"Most other drinks, even iced tea and stuff like that, have sugars, and eventually sugar is stored as fat," Knaub said. "Water is pure as it can be, and most of our bodies are made up of water so it's good for us, especially when it's hot outside."

9. Burpees and lunges

Burpees and lunges are two exercises that, like a pull-up or push-up, don't require any equipment.

A burpee is done by squatting down and placing your hands on the ground. From there, jump into a push-up position and then jump back into the original position. Standing back up.

A lunge is done by stepping forward with one leg and bending the knee, while dropping the other knee to the ground.

"Burpee is a total body exercise and will get your heart thumping," Swope said. "Lunges are a great lower body exercise that you can add a curl, press or row to with bottled water."